Enhancing Bias Stress Stability and VTH Recovery of n-Type SnO₂:Ge Thin Film Transistor

Excellent positive (PBS) and negative (NBS) bias stress stability and threshold voltage (VTH) recovery were found in 12.2 % germanium (Ge) doped tin oxide (SnO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>:Ge) thin film transistor (TFT). Ge doping curbed oxygen vacancies in SnO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> increasing on/off current ratio (~10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup>)., and field effect mobility (16.30 cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>/V-s) while reducing subthreshold slope (78 mV/dec) of TFT. XPS and photoluminescence (PL) characterizations revealed dominant defect states within Sn02:Ge those have been found responsible for charge trapping and release hence for V TH shift and its recovery further tailored by optimized Ge doping